Clinical and laboratory features of canine Anaplasma platys infection in 32 naturally infected dogs in the Mediterranean basin.

Since the first description of Anaplasma platys Infection (ApI), the disease has been sporadically reported worldwide. Whereas it is considered a subclinical disease in the United States or in Australia, severe cases are reported in Europe. Thus far, little information is available regarding the clinical and laboratory findings associated with the disease and the implication of co-infections with other vector-borne pathogens (VBPs) in Southern Europe. The purpose of the study was to describe clinical and laboratory findings in PCR-confirmed naturally infected dogs in the Mediterranean Basin, and to assess the potential impact of co-infections with other VBPs. This is a retrospective analysis of medical records from 32 client-owned dogs diagnosed with ApI using PCR-based assays. Anorexia (62.5%) and weight loss (43.8%) were the major changes, whereas lethargy was less frequent (34.4%). Lymphadenomegaly (43.8%), hyperthermia (40.6%) and hemorrhage (37.5%) were frequent clinical abnormalities, whereas cutaneous signs (31.3%), musculoskeletal disorders (21.9%), splenomegaly (15.6%), dehydration and ocular inflammation (12.5%) were less common. Hematological abnormalities included thrombocytopenia (81.0%), anemia (81.0%), leukocytosis (33.3%) and leucopenia (23.8%). Seven dogs (33.3%) were severely thrombocytopenic. Among the 28 dogs with complete testing, 15 and 13 were mono- and co-infected, respectively. Co-infections included Ehrlichia canis (3 dogs), Leishmania infantum (4), Babesia vogeli (2) and Hepatozoon canis (5). One dog was infected concurrently with Anaplasma platys, Ehrlichia canis and Babesia vogeli. The 1-month mortality rate was 23.9% and only 38.1% improved. In the univariate analysis the 15 mono- and the 13 co-infected dogs did not differ regarding the relative frequencies of clinical and laboratory findings. Sequencing and phylogenetic analyses suggested the existence of 2 different groups of strains: one of them might have higher pathogenicity. In all, ApI was associated with a wide variety of non-specific clinical findings. The most common laboratory findings were thrombocytopenia and anemia. Co-infections were frequent but appeared of limited clinical impact. The absence of improvement despite appropriate treatment, high frequency of hemorrhagic disorders, and case fatalities, suggested the existence of pathogenic European strains supported by subsequent molecular analyses.

Update on epidemiology of canine babesiosis in Southern France.

BACKGROUND: Canine babesiosis is an emerging or re-emerging disease caused by Babesia and Theileria protozoans, also called piroplasms, transmitted by Ixodid ticks. In Europe, four etiological agents have been identified to date, namely Babesia canis, B. vogeli, B. gibsoni and Theileria annae. France has a high prevalence of canine babesiosis and two tick species, Dermacentor reticulatus and Rhipicephalus sanguineus, are supposed to transmit B. canis and B. vogeli respectively. In southern France, where dog infections with B. vogeli were recently confirmed, no comprehensive study was performed to date on piroplasm species infecting dogs. Thus, a large scale survey involving veterinary clinics, kennels and tick collection from the environment was conducted from 2010 to 2012 in this area. RESULTS: From 2010 to 2012, 140 dog blood samples and 667 ticks were collected. All blood and a subset of ticks were screened for the presence of piroplasms by PCR amplification of 18S rDNA. B. vogeli, B. canis and T. annae were detected in 13.6, 12.9 and 0.7 % dogs respectively. B. vogeli and B. canis were detected in 10.5 % and in 1.6 % R. sanguineus ticks including 1.3 % co-infections. B. canis was the only species detected in D. reticulatus ticks (9.7 %). B. canis infections were only recorded in the southwest of France whereas B. vogeli was mainly found in the southeast. Finally, a significantly higher prevalence of B. vogeli infection was found in Gard compared to Corsica and Drôme regions, both in dogs (p < 0.002) and R. sanguineus ticks (p < 0.02) although R. sanguineus was the main ticks species removed from dogs in those three areas. CONCLUSIONS: The survey confirmed the circulation of both B. canis and B. vogeli in dogs in southern France with differences in distribution probably linked to the distribution of their respective vectors. It also showed differences in prevalence of B. vogeli infection in areas similar in terms of risk of dogs infestation with R. sanguineus. Further studies focusing on genetic and microbiota of R. sanguineus ticks should be conducted to explore other biological interactions that may explain the differences observed.

Diagnosis and incidence risk of clinical canine monocytic ehrlichiosis under field conditions in Southern Europe.

BACKGROUND: Canine Monocytic Ehrlichiosis (CME), due to the bacterium Ehrlichia canis and transmitted by the brown dog tick Rhipicephalus sanguineus, is a major tick-borne disease in southern Europe. In this area, infections with other vector-borne pathogens (VBP) are also described and result in similar clinical expression. The aim of the present study was to evaluate the incidence risk of clinical CME in those endemic areas and to assess the potential involvement of other VBP in the occurrence of clinical and/or biological signs evocative of the disease. METHODS: The study was conducted from April to November 2011 in veterinary clinics across Italy, Spain and Portugal. Sick animals were included when fitting at least three clinical and/or biological criteria compatible with ehrlichiosis. Serological tests (SNAP®4Dx, SNAP®Leish tests, Idexx, USA) and diagnostic PCR for E. canis, Anaplasma platys, Anaplasma phagocytophilum, Babesia spp, Hepatozoon canis and Leishmania infantum detection were performed to identify the etiological agents. Ehrlichiosis was considered when three clinical and/or biological suggestive signs were associated with at least one positive paraclinical test (serology or PCR). The annual incidence risk was calculated and data were geo-referenced for map construction. The probabilities of CME and other vector-borne diseases when facing clinical and/or biological signs suggestive of CME were then evaluated. RESULTS: A total of 366 dogs from 78 veterinary clinics were enrolled in the survey. Among them, 99 (27%) were confirmed CME cases, which allowed an estimation of the average annual incidence risk of CME amongst the investigated dog population to be 0.08%. Maps showed an increasing gradient of CME incidence risk from northern towards southern areas, in particular in Italy. It also suggested the existence of hot-spots of infections by VBP in Portugal. In addition, the detection of other VBP in the samples was common and the study demonstrated that a dog with clinical signs evocative of CME is as likely to be positive to Ehrlichia canis as to another VBP. CONCLUSIONS: The study confirms the endemicity of CME in southern Europe and highlights the difficulties encountered by veterinarians to differentiate CME from other vector-borne diseases under field conditions.

Study of ehrlichiosis in kennel dogs under treatment and prevention during seven months in Dakar (Senegal).

In Dakar kennels where morbidity and mortality attributed to diseases transmitted by ticks were high, we conducted a field study to assess the prevalence of Ehrlichia canis, Anaplasma platys and Babesia spp. infections in two kennels (n = 34 dogs) and to study the impact of tick protection. The first day of the study, the E. canis PCR were positive in 18 dogs (53%). A. platys was found in one dog and all dogs were negative for Babesia spp. After one month of doxycycline treatment, the number of PCR positive dogs decreased significantly to 2 (5.9%). During seven months, all dogs were treated monthly topically with a novel combination (Certifect(®), Merial) delivering at least 6.7 mg fipronil/kg body weight, 8.0mg amitraz/kg and 6 mg (S)-methoprene/kg. The number of PCR positive dogs remained stable all over the seven months, with 4 dogs being positive at Day 90 and 2 at Day 210. The combination of treatment and monthly prevention had a significant effect in the two kennels. All dogs remained healthy, which was not the case in previous years.